QTL Mapping of Low-Temperature Germination Ability in the Maize IBM Syn4 RIL Population.
QTL Mapping of Low-Temperature Germination Ability in the Maize IBM Syn4 RIL Population.
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玉米 IBM Syn4 RIL 群体低温发芽能力的 QTL 定位
DOI：
10.1371/journal.pone.0152795
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发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Lee M
中科院分区：
文献类型：
--
作者：
Hu S;Lübberstedt T;Zhao G;Lee M
低温是影响早春玉米播种的主要因素。因此，提高玉米种子萌发期对低温的耐受性对玉米育种具有重要意义。然而，有关玉米低温发芽能力的QTL却知之甚少。以B73×Mo17(IBM)Syn4重组自交系群体的243个品系为材料，对其低温发芽力进行了QTL分析。在低温(12℃/16h、18℃/8h)和最适温度(28℃/24小时)条件下，发芽相关性状在亲本间存在显著差异。仅检测到3个控制最适温度发芽率的QTL。在第4、5、6、7、9染色体上检测到6个控制低温发芽率的QTL，单个QTL的贡献率在3.39%~11.29%之间。此外，在第4、5、6、9染色体上检测到6个控制低温初生根长的QTL，其贡献率在3.96%~8.41%之间。4对QTL位于同一染色体位置，共同控制低温条件下的发芽率和初生根长。距离最近的标记分别是第4染色体上的umc1303(265.1 cM)，第5染色体上的umc1(246.4 cM)，第6染色体上的umc62(459.1 cM)，第9染色体上的bn114.28a(477.4 cM)。基于玉米遗传学和基因组学数据库(http://www.maizegdb.org).)，从9个不同的区间中提取了3155个候选基因选择了5个影响种子萌发和幼苗低温生长的候选基因进行分析。本研究结果为玉米种子萌发期耐冷性的精细定位、分子标记辅助育种和耐冷性功能研究奠定了基础。
Low temperature is the primary factor to affect maize sowing in early spring. It is, therefore, vital for maize breeding programs to improve tolerance to low temperatures at seed germination stage. However, little is known about maize QTL involved in low-temperature germination ability. 243 lines of the intermated B73×Mo17 (IBM) Syn4 recombinant inbred line (RIL) population was used for QTL analysis of low-temperature germination ability. There were significant differences in germination-related traits under both conditions of low temperature (12°C/16h, 18°C/8h) and optimum temperature (28°C/24h) between the parental lines. Only three QTL were identified for controlling optimum-temperature germination rate. Six QTL controlling low-temperature germination rate were detected on chromosome 4, 5, 6, 7 and 9, and contribution rate of single QTL explained between 3.39%~11.29%. In addition, six QTL controlling low-temperature primary root length were detected in chromosome 4, 5, 6, and 9, and the contribution rate of single QTL explained between 3.96%~8.41%. Four pairs of QTL were located at the same chromosome position and together controlled germination rate and primary root length under low temperature condition. The nearest markers apart from the corresponding QTL (only 0.01 cM) were umc1303 (265.1 cM) on chromosome 4, umc1 (246.4 cM) on chromosome 5, umc62 (459.1 cM) on chromosome 6, bnl14.28a (477.4 cM) on chromosome 9, respectively. A total of 3155 candidate genes were extracted from nine separate intervals based on the Maize Genetics and Genomics Database (http://www.maizegdb.org). Five candidate genes were selected for analysis as candidates putatively affecting seed germination and seedling growth at low temperature. The results provided a basis for further fine mapping, molecular marker assisted breeding and functional study of cold-tolerance at the stage of seed germination in maize.